Research On High-Speed Video Acquisition And Analysis Technology Of Shower Nozzle’s Spray Field Based On DSP

Shower nozzle is an indispensable item in modern home life. In the traditional shower nozzle’s design process, we always focus on the nozzles’ structure, durable and water means. With society develops, people begin to realize it’s important to water conservation and energy efficiency, in order to protect our resistance to the survival of the earth’s ecosystem. What’s more, China is a water-poor country; people’s per capita water resource is only a quarter of the world’s average. So, it’s particularly important to develop water-saving shower nozzles. But in the process of developing water-saving shower nozzle, how to get the best cleaning results and comfortable shower experience has become a problem.In this case, this paper studies proceed from the actual shower nozzle, build a non-contact shower spray field measurement system with image measurement technology. System measures the shower nozzle’s injection rate, spray angle, and spray gas-liquid distribution to analysis the spray field. The main thesis of this paper include:The feasibility analysis of no-contact image measurement method using in shower nozzles’spray field analysis, high-speed video acquisition system design and debugging, and development and implement the image measurement software on PC.The hardware part of the system is high-speed image acquisition circuit, which consists of three parts:Video decoding, FPGA-based high-speed image acquisition, and data exchange between FPGA and DSP. Video decoding circuit used a SAA7111A to decode the PAL video signal, and then FPGA complete the high-speed image data acquisition. In order to improve image acquisition speed, a high-speed ping-pong buffer is designed in the data acquisition circuit. So, when FPGA storage image data in one memory chip, DSP can get data from another memory chip through the FIFO. The DSP’s task is to preprocess the image data, and then sent the image data to the host computer with USB2.0high-speed bus. System’s software developing is mainly responsible for FPGA and DSP embedded system, and image measurement algorithm researching on the host-side. To study the spray field parameters with non-contact image measurement algorithms, this paper tested some image algorithms, and filtering out some efficient filtering and extraction algorithm. Finally, the system successfully measured the spray field parameters.